Grinding wheel dressing



March 1, 1960 L. DUNCAN GRINDING WHEEL DRESSING Filed Sept. 16, 1953 INVENTOli Lane Duncan ATTORNEYS United States Patent This invention relates to grinding wheel dressing and more particularly to a method and apparatus for accurately dressing a face and a radius at the edge of the face of a rotatable grinding wheel.

In the art of grinding Wheel dressing increasing emphasis is being placed upon accurate dressing of a radius at the edgeof the periphery of the grinding wheel as well as the periphery. This radius may be utilized, for example, in grinding a headed fastener when it is necessary to form a radius at the junction of thehead and shank of the ground fastener. Because the strength of the fastener is governed to some degre by the junction of the head and the grip, increasedconcern has been placed upon the configuration at this point and an accurate radius at this junstion, which may be generated during a grinding operation, is necessary. Often a radius burnishing operation may be added to increase the strength of the fastener and the radius must be accurate to conform to a steel burnishing roller, thus adding another reason for the necessity of generating an accurate radius 7 number of articles.

It has previously beenthe practice, when generating a radius at the edge of a periphery of a grinding wheel, to dress or generate the radius with a pivotally mounted dressing tool and then lock this tool in horizontal position and move it transversely across the peripheral face of the wheel to finish the dressing operation. In using the same dressing tool, which conventionally is a diamond, for both the radius and transverse dressing any wear incurred by the dressing tool while moving it across the periphery of the grinding wheel would be reflected in the size and tolerance of the next radius dressed. With the previous tolerance allowances this was a satisfactory operation. However, with the close tolerances now desirable, for the reasons discussed above, the dressing operation using one dressing tool for both the radius and transverse dressing is not satisfactory, as the close tolerances cannot be adequately held. Therefore, it is the principal object of this invention to provide a method and apparatus for accurately dressing both the face of a grinding wheel and a radius at the edge of the face.

In general, this invention contemplates providing two dressing tools for accomplishing the dressing operation. The face of the grinding wheel is adapted to be contacted by a heavy dressing diamond mounted on a slide ahead of a fine radius dressing diamond which is adapted to dress a radius at the edge of the face. By adjusting the heavy diamond to dress the face of the grinding wheel ahead of the radius diamond and allowing the fine radius diamond to principally dress the radius, wear on the fine dressing point of the radius diamond is diminished. Therefore, when the radius is dressed by the fine diamond a uniform and accurate radius is generated. In operation, the slide carrying the heavy transverse diamond and the fine radius diamond is stopped by an adjustable stop at precisely the point where the radius diamond is aligned with the center of the radius to be generated.

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2 a l The radius diamond is then swimg90 about a pivotal mounting coincident with the center of the desired radius to dress a radius tangent to both the periphery and radial face of the grinding wheel.

Further objects and advantages of the invention will be pointed out in the following detailed description and claims taken in connection with the accompanying drawing, which discloses, by way of example, the principle of this invention and the best mode which has been contemplate of applying that principle.

In the drawing: r

Fig. 1 is a top plan view of a portion of the apparatus of this invention showing the apparatus dressing a face of a grindingwheel;

Fig. 2 is a top plan view similar tov Fig. 1 showing the dressing apparatus in position to dress the radius at the edge of the face of a grinding wheel;

Fig. 3 is a side elevation view, partly in section, showing the manner in which the radius dressing diamond could be mounted; V

Fig. 4 is a schematic illustration of this invention being practiced to dress the face of a grinding wheel; and

Fig. 5 is a schematic illustration of dressing a radius at the edge of the face of a grinding wheel.

Referring to the drawing, reference numeral 10 represents a grinding wheel having a face 12 which is desired to be dressed and a radius 14 at the edge of the face which is also desiredto be dressed. As stated previously, the tolerance of the article ground by this radius is quite close andtherefore it is necessary to dress this radius quite accurately. This invention provides a method and apparatus for dressing both the face of the grinding wheel and accurately dressing this radius. r

A dressing tool assembly 16is suitably mounted in a slideway 18 of a bed 20 for transverse movement parallel with the face 12 ofthe grinding wheel 10. The dressing assembly carries a relatively heavy face dressing diamond 22 and a relatively light radius dressing diamond 24.

is pivotally supported from bracket 30 ata pivot point' 32. A suitable handle 34 is provided to swing bracket 28 and hence diamond 24 about the pivot point 32. A locking screw 36 may be threaded through the bracket 30 to abut against the holder 28 for locking the diamond 24 during the transverse dressing operation. A conventional feed assembly 38 is provided for feeding the dress ing tool assembly radially into the grinding wheel for adjusting the amount of dressing".

The bed 20 of the apparatus includes a stop 40 against which an edge of the dressing assembly is adapted to abut at the end of its stroke, and this stop 40 is adjustable through the intermediary of adjusting handle 42 in a conventional manner. The stop 40 is adjusted such that the pivot point 32 of the radius diamond is aligned with the center of the radius 14 desired to be dressed.

In operation, the dressing assembly 16 is adapted to move along slideway 18 in machine bed 20 in the direction of the arrows shown in Figs. 1 and 2. With this movement and with relatively heavy traverse dressing diamond 22 adjusted such that the point thereof is aligned with the point of relatively light radius dressing diamond 24, during the traverse of the dressing tool assembly 16 the heavy diamond 22 will accomplish most.

Patented Mar. 1,1960 7 I of the operation of dr essing the face 12 of the grinding wheel 10. Thus, any wear which will occur will be reflected in the wearing down of the point 22 of the relatively heavy face dressing diamond. For accuracy in dressing the radius 14 the light radius dressing diamond 2 4v is utilized. Stop 40 is adjusted by handle 42 to stop the dressing assembly '16 at the end of its traverse and t the: edge of the grinding wheel produces an accurateradius which may be utilized to grind articles having close tolerance limits. I

The various portions of the apparatus are shown in simplified form for the purpose of teaching the invention to one skilled in the art. It is obvious, however, that various modifications, changes and substitutions may be utilized without departing from the spirit of the invention. The invention is adapted to dress grinding wheels in various types of grinding machines and is not limited to that illustrated in the above described embodiment. It is the intention therefore that the scope of this invention be limited only by the appended claims and; the reasonable equivalents thereof.

I claim:

1. An apparatus for dressing a peripheral face of a cylindrical grinding wheel and accurately refining and dressing a radius at the edge of the face, said apparatus comprising; a support, a slide movable on said support only parallel to the face of the rotating grinding wheel, a first dressing tool carried by said slide for dressing the face of said grinding wheel, said dressingtool being independently adjustable toward and away from the grinding wheel, a second dressing tool, means pivotally mount-,

ing said second dressing tool on said slide independent of said first dressing tool, said second dressing tool positioned adjacent the first dressing tool such that the first dressing tool will contact the periphery of the grinding wheel first and will accomplish most of the dressing of the face of said grinding wheel, an adjustable stop on said support for. stopping the movement of said slide when said second dressing tool is a predetermined distance past the edge of said grinding wheel and the axis of said pivotal support is coincident with the axis ofthe radius to be dressed, and means for moving the second dressing tool along a radius defined by its pivotal support to thereby dress the radius at the edge of the face of the grinding wheel.

2. An apparatus for dressing a peripheral face of a grinding Wheel and accurately refining and dressing a radius at the edge of the peripheral face and a radial face of the grinding wheel, said apparatus comprising; a relatively heavy diamond dressing tool, slide means supporting the heavy diamond dressing tool for relative transverse movement only parallel to the peripheral surface of said grinding wheel, a relatively fine diamond dressing tool carried by said support means for transverse movement parallel to the peripheral surface of said grinding wheel for dressing behind said first diamond dressing tool, a pivotal support for said fine diamond tool on said slide means, said pivotal support being independent of said relatively heavy diamond dressing tool, lock means for normally locking said fine dressing tool during the transverse movement of said slide means, stop means for stopping the relative transverse movement of said slide means and said grinding wheel when said second fine diamond dressing tool is aligned with the center of a radius to be generated on the edge of the peripheral surface and the radial face of the grinding wheel, and means for moving said second fine dressing tool in an are as defined by the pivotal support therefor and about the center of the radius to be dressed when said slide means is against said stop means and said lock means is unlocked to thereby accurately generate the radius at the edge of the peripheral face of said grinding Wheel.

3. A method of dressing a peripheral surface and a radius at the edge of the peripheral surface of a grinding Wheel, said method comprising; transversely moving a first dressing tool and a rotating cylindrical grinding wheel relative to each other so that the tool Will move parallel to the periphery of the wheel and accomplish,

the dressing thereof, following the relative movement ofsaid first dressing tool with a second pivotally mounted dressing tool which ,will not dress the periphery of the grinding wheel, locking the second dressing tool relative to said pivotal mounting during the. traverse of said first dressing tool and wheel, stopping the relative transverse movement of the dressing tools and the grinding wheel when said second dressing tool is a distance equal to the desired dressed radius from the edge of the peripheral surface of the grinding wheel, and swinging the second dressing tool about its pivot to generate an accurate radius tangent with the periphery and radial face of the grinding wheel.

References Cited in the file of this patent,

UNITED STATES PATENTS 2,355,020 Turrettini Aug. 1, 1944 

